Sunday marked an anniversary most Beatles fans would rather forget: the day in 1970 when Paul McCartney announced to the world that the Beatles were essentially over. To promote his first solo album, McCartney, Paul issued a four-page interview with himself. The band, McCartney wrote, was divided over "personal differences, business differences, musical differences," adding, "Temporary or permanent? I don't know." To his own question, "Do you foresee a time when Lennon-McCartney become an active songwriting partnership again?" he bluntly answered, "No."

The papers documenting the legal end of the Beatles aren't easy to examine. They're stored an hour outside London at the National Archives, home to historical documents dating back 1000 years, and I had to look at them in a windowless room, locked from the outside. I wasn't allowed to photograph any of the papers and could only use a pencil to take notes.

Despite these restrictions – and with the help of some interviews of some crucial players – I was able to put together a timeline of the last days of the Beatles. Here's some of what I gleaned.

March 20: Allen Klein, then handling the Beatles' business affairs, asks EMI to delay the release of McCartney, which Paul wants out on April 17. With the Let It Be album already scheduled for that month, and Ringo about to unveil his solo album Sentimental Journey, Klein is concerned about a glut of Beatle product in the stores.

March 23: Unaware of Klein's maneuver, Paul finishes up McCartney at EMI Studio. The same day, Klein meets personally with EMI and repeats his (and other Beatles') demands. EMI agrees to postpone McCartney.

March 31: John and George write a letter to Paul to explain their actions: "We thought a lot about yours and the Beatles LPs – and decided it's stupid for Apple to put out two big albums within seven days of each other. … We're sorry it turned out like this – it's nothing personal." Later that day, Ringo hand-delivers the letter to a shocked Paul at his London home; Paul reads it, yells at him and asks him to leave. "I got really angry when Ringo told me that Klein had told him my record was not ready," Paul says in his court affidavit. Ringo convinces John and George to let Paul's album come out as planned and to delay Let It Be by a month.

April 1: Phil Spector, hired by Klein to finish Let It Be, overdubs strings, a harp, a choir and additional drums onto "The Long and Winding Road" without McCartney's knowledge.

April 7: Paul's lawyers announce the release of McCartney, and the four Beatles agree to meet for the first time in months on Friday, April 10, to discuss the Let It Be movie. The same day, Paul's statement – which the other Beatles are unaware of – is delivered to the Apple press office, for distribution with the first 100 press copies of McCartney.

April 8: Xeroxes of Paul's press release are hand-delivered to writers at the London Evening Standard and the Daily Mirror, who are told not to publish it for two more days.

April 9: A day early, the Daily Mirror runs an article declaring Paul has left the Beatles. Paul calls John, who's already heard about the announcement from the Evening Standard'sRay Connolly. Beatle associate Mal Evans hears a radio report and tells George at his Friar Park home outside London.

April 10: Paul's announcement goes global and fans begin congregating outside Apple headquarters; a TV reporter on the scene declares, "The event is so momentous that historians may mark it as a landmark in the decline of the British Empire." Not surprisingly, McCartney's team sends a cable to Apple canceling the planned Beatles meeting that day.

April 16: Stung by the way the public is blaming him for the Beatles' breakup, Paul calls the Evening Standard's Connolly for an interview. Over lunch, Paul claims Yoko Ono's presence played a role in intragroup tensions and admits he threw Ringo out of his house. "I didn't leave the Beatles," he says. "The Beatles have left the Beatles. But no one wanted to be the one to say the party's over." When John reads the interview in print a few days later – especially the part where Paul complains about the female choir added onto "The Long and Winding Road" – he cracks, "Is that what this is all about—those bloody girls?"